Question

The brakes on an elevator of weight 50,000 N act upward with a force of 100,000 N the acceleration of elevator while braking would be____A) 9.8 m/s^2 downB) 1.9 m/s^2 upC) 3.17 m/s^2 upD) 9.8 m/s^2 up

Answer 1

Using newton's second law:

`\begin{gathered} \Sigma Fy=ma \\ 50000-100000=(50000)/(9.8)a \\ solve_{\text{ }}for_{\text{ }}a: \\ a=9.8((50000-100000)/(5000)) \\ a=-9.8m/s^2 \end{gathered}`

Answer:

D) 9.8 m/s^2 up